#
# gPrime - A web-based genealogy program
#
# Copyright (C) 2007 Zsolt Foldvari
# Copyright (C) 2008 Brian G. Matherly
# Copyright (C) 2013 Vassilii Khachaturov
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

"""PS/PDF output generator based on Cairo.
"""

#------------------------------------------------------------------------
#
# Python modules
#
#------------------------------------------------------------------------
import logging

#-------------------------------------------------------------------------
#
# GTK modules
#
#-------------------------------------------------------------------------
import gi
gi.require_version('Pango', '1.0')
gi.require_version('PangoCairo', '1.0')
from gi.repository import Pango, PangoCairo
import cairo

#------------------------------------------------------------------------
#
# Gprime modules
#
#------------------------------------------------------------------------
import gprime.plugins.lib.libcairodoc as libcairodoc
from gprime.plug.docgen import INDEX_TYPE_ALP, INDEX_TYPE_TOC
from gprime.errors import ReportError
from gprime.const import LOCALE as glocale
_ = glocale.translation.gettext

#------------------------------------------------------------------------
#
# Set up logging
#
#------------------------------------------------------------------------
LOG = logging.getLogger(".cairodoc")

#------------------------------------------------------------------------
#
# Constants
#
#------------------------------------------------------------------------

# resolution
DPI = 72.0

#------------------------------------------------------------------------
#
# CairoDocgen class
#
#------------------------------------------------------------------------
class CairoDocgen(libcairodoc.CairoDoc):
    """Render the document into a file using a Cairo surface.
    """
    def create_cairo_surface(self, fobj, width_in_points, height_in_points):
        # See
# http://cairographics.org/documentation/pycairo/3/reference/surfaces.html#class-pssurface-surface
        # for the arg semantics.
        raise "Missing surface factory override!!!"

    def run(self):
        """Create the output file.
        The derived class overrides EXT and create_cairo_surface
        """
        # get paper dimensions
        paper_width = self.paper.get_size().get_width() * DPI / 2.54
        paper_height = self.paper.get_size().get_height() * DPI / 2.54
        page_width = round(self.paper.get_usable_width() * DPI / 2.54)
        page_height = round(self.paper.get_usable_height() * DPI / 2.54)
        left_margin = self.paper.get_left_margin() * DPI / 2.54
        top_margin = self.paper.get_top_margin() * DPI / 2.54

        # create cairo context and pango layout
        filename = self._backend.filename
        # Cairo can't reliably handle unicode filenames on Linux or
        # Windows, so open the file for it.
        with open(filename, 'wb') as fd:
            try:
                surface = self.create_cairo_surface(fd, paper_width,
                                                    paper_height)
                surface.set_fallback_resolution(300, 300)
                cr = cairo.Context(surface)
                fontmap = PangoCairo.font_map_new()
                fontmap.set_resolution(DPI)
                pango_context = fontmap.create_context()
                options = cairo.FontOptions()
                options.set_hint_metrics(cairo.HINT_METRICS_OFF)
                PangoCairo.context_set_font_options(pango_context, options)
                layout = Pango.Layout(pango_context)
                PangoCairo.update_context(cr, pango_context)
                # paginate the document
                self.paginate_document(layout, page_width, page_height,
                                       DPI, DPI)
                body_pages = self._pages

                # build the table of contents and alphabetical index
                toc_page = None
                index_page = None
                toc = []
                index = {}
                for page_nr, page in enumerate(body_pages):
                    if page.has_toc():
                        toc_page = page_nr
                    if page.has_index():
                        index_page = page_nr
                    for mark in page.get_marks():
                        if mark.type == INDEX_TYPE_ALP:
                            if mark.key in index:
                                if page_nr + 1 not in index[mark.key]:
                                    index[mark.key].append(page_nr + 1)
                            else:
                                index[mark.key] = [page_nr + 1]
                        elif mark.type == INDEX_TYPE_TOC:
                            toc.append([mark, page_nr + 1])

                # paginate the table of contents
                rebuild_required = False
                if toc_page is not None:
                    toc_pages = self.__generate_toc(layout, page_width,
                                                    page_height, toc)
                    offset = len(toc_pages) - 1
                    if offset > 0:
                        self.__increment_pages(toc, index, toc_page, offset)
                        rebuild_required = True
                else:
                    toc_pages = []

                # paginate the index
                if index_page is not None:
                    index_pages = self.__generate_index(layout, page_width,
                                                        page_height, index)
                    offset = len(index_pages) - 1
                    if offset > 0:
                        self.__increment_pages(toc, index, index_page, offset)
                        rebuild_required = True
                else:
                    index_pages = []

                # rebuild the table of contents and index if required
                if rebuild_required:
                    if toc_page is not None:
                        toc_pages = self.__generate_toc(layout, page_width,
                                                        page_height, toc)
                    if index_page is not None:
                        index_pages = self.__generate_index(layout, page_width,
                                                            page_height, index)

                # render the pages
                if toc_page is not None:
                    body_pages = body_pages[:toc_page] + toc_pages + \
                                 body_pages[toc_page+1:]
                if index_page is not None:
                    body_pages = body_pages[:index_page] + index_pages + \
                                 body_pages[index_page+1:]
                self._pages = body_pages
                for page_nr in range(len(self._pages)):
                    cr.save()
                    cr.translate(left_margin, top_margin)
                    self.draw_page(page_nr, cr, layout,
                                   page_width, page_height,
                                   DPI, DPI)
                    cr.show_page()
                    cr.restore()

                # close the surface (file)
                surface.finish()

            except IOError as msg:
                errmsg = "%s\n%s" % (_("Could not create %s") % filename, msg)
                raise ReportError(errmsg)
            except Exception as err:
                errmsg = "%s\n%s" % (_("Could not create %s") % filename, err)
                raise ReportError(errmsg)

    def __increment_pages(self, toc, index, start_page, offset):
        """
        Increment the page numbers in the table of contents and index.
        """
        for n, value in enumerate(toc):
            page_nr = toc[n][1]
            toc[n][1] = page_nr + (offset if page_nr > start_page else 0)
        for key, value in index.items():
            index[key] = [page_nr + (offset if page_nr > start_page else 0)
                          for page_nr in value]

    def __generate_toc(self, layout, page_width, page_height, toc):
        """
        Generate the table of contents.
        """
        self._doc = libcairodoc.GtkDocDocument()
        self._active_element = self._doc
        self._pages = []
        write_toc(toc, self)
        self.paginate_document(layout, page_width, page_height, DPI, DPI)
        return self._pages

    def __generate_index(self, layout, page_width, page_height, index):
        """
        Generate the index.
        """
        self._doc = libcairodoc.GtkDocDocument()
        self._active_element = self._doc
        self._pages = []
        write_index(index, self)
        self.paginate_document(layout, page_width, page_height, DPI, DPI)
        return self._pages

def write_toc(toc, doc):
    """
    Write the table of contents.
    """
    if not toc:
        return

    doc.start_paragraph('TOC-Title')
    doc.write_text(doc.toc_title)
    doc.end_paragraph()

    doc.start_table('toc', 'TOC-Table')
    for mark, page_nr in toc:
        doc.start_row()
        doc.start_cell('TOC-Cell')
        if mark.level == 1:
            style_name = "TOC-Heading1"
        elif mark.level == 2:
            style_name = "TOC-Heading2"
        else:
            style_name = "TOC-Heading3"
        doc.start_paragraph(style_name)
        doc.write_text(mark.key)
        doc.end_paragraph()
        doc.end_cell()
        doc.start_cell('TOC-Cell')
        doc.start_paragraph(style_name)
        doc.write_text(str(page_nr))
        doc.end_paragraph()
        doc.end_cell()
        doc.end_row()
    doc.end_table()

def write_index(index, doc):
    """
    Write the alphabetical index.
    """
    if not index:
        return

    doc.start_paragraph('IDX-Title')
    doc.write_text(doc.index_title)
    doc.end_paragraph()

    doc.start_table('index', 'IDX-Table')
    for key in sorted(index.keys()):
        doc.start_row()
        doc.start_cell('IDX-Cell')
        doc.start_paragraph('IDX-Entry')
        doc.write_text(key)
        doc.end_paragraph()
        doc.end_cell()
        doc.start_cell('IDX-Cell')
        doc.start_paragraph('IDX-Entry')
        pages = [str(page_nr) for page_nr in index[key]]
        doc.write_text(', '.join(pages))
        doc.end_paragraph()
        doc.end_cell()
        doc.end_row()
    doc.end_table()

#------------------------------------------------------------------------
#
# PdfDoc class
#
#------------------------------------------------------------------------
class PdfDoc(CairoDocgen):
    """Render the document into PDF file using Cairo.
    """
    def create_cairo_surface(self, fobj, width_in_points, height_in_points):
        return cairo.PDFSurface(fobj, width_in_points, height_in_points)

#------------------------------------------------------------------------
#
# PsDoc class
#
#------------------------------------------------------------------------
class PsDoc(CairoDocgen):
    """Render the document into PS file using Cairo.
    """
    EXT = 'ps'
    def create_cairo_surface(self, fobj, width_in_points, height_in_points):
        return cairo.PSSurface(fobj, width_in_points, height_in_points)
